Lecture 7: Ionic Bonding

Question 1

What is a chemical bond?

Answer 1

An attractive force that holds two or more atoms together

Question 2

What are the four types of chemical bonds?

Answer 2

• Ionic
• Covalent
• Dative
• Metallic

Question 3

What do most atoms adjust their valence shells to?

Answer 3

8 e^-

Question 4

Which atoms do not obey the 8 e^- rule?

Answer 4

Transition metals using their d-orbitals (they use the 18 e^- rule)

Question 5

How will a proton act on another proton?

Answer 5

They will repel

Question 6

How will an electron act on a proton?

Answer 6

They will attract

Question 7

How will a neutron act on an electron?

Answer 7

It will not

Question 8

How is the force acting on each particle linked to the size of the charge?

(HINT: Columb’s Law)

Answer 8

They are proportional

Question 9

How is the force acting on each particle linked to the distance between them?

(HINT: Coulomb’s Law)

Answer 9

Inverse square

Question 10

What is electronegativity?

Answer 10

The ability of an atom to attract electrons in a chemical bond

Question 11

What factors affect electronegativity?

Answer 11

• The charge of the nucleus
• Atomic radius
• Screening (shielding)

Question 12

Which element is most electronegative?

Why?

Answer 12

Fluorine

Small atomic radius, high nuclear charge

Question 13

Explain ionic bonds

Answer 13

Bonds between metals and non-metals

Metals donate electrons

Non-metals gain electrons

This forms oppositely-charged ions

The ions then attract each other

Question 14

Describe the properties of an ionic bond (4+1)

Answer 14

• Non-directional
• The compound will dissolve and dissociate in polar solvents
• (the separated ions are solvated)
• The bonds can be broken by melting
• The compounds have no overall charge

Question 15

Which factors favour ionic bonding? (6)

Answer 15

• Low IE of the metal
• High EA of the non-metal
• Small non-metal
• Low anion charge
• Large electronegativity difference between the ions
• High lattice energy

Question 16

Which characteristics give an ion more polarising power?

Answer 16

• Smaller atomic radius
• Higher charge

Question 17

What are Fajan’s Rules?

Answer 17

An ionic compound is more likely to show covalent character if the cation is very polarising or the anion is very polarisable

Question 18

Name the following ions:

• NH₄⁺
• CN^-
• CO₃^2-
• MnO₄^-
• C₂O₄^2-
• SO₄^2-

Answer 18

• Ammonium
• Cyanide
• Carbonate
• Permanganate
• Oxalate
• Sulphate

Question 19

Give the formulae for the following ions:

• Peroxide
• Hydroxide
• Acetate
• Nitrate
• Carbonate
• Phosphate
• Dichromate

Answer 19

• O₂^2-
• HO^-
• CH₃CO₂^-
• NO₃^-
• CO₃^2-
• PO₄^3-
• Cr₂O₇^2-